Shows the list of components to the user during installer operation,
and starts a component when it is selected. Main-menu's
questions are set to priority medium, so if your priority is set to
high or critical (high is the default), you will not see the menu. On
the other hand, if there is an error which requires your intervention,
the question priority may be downgraded temporarily to allow you
to resolve the problem, and in that case the menu may appear.

You can get to the main menu by selecting the Go Back button
repeatedly to back all the way out of the currently running component.

localechooser

Allows the user to select localization options for the installation and
the installed system: language, country and locales. The installer will
display messages in the selected language, unless the translation for
that language is not complete in which case some messages may be shown
in English.

console-setup

Shows a list of keyboards, from which the user chooses the model which
matches his own.

hw-detect

Automatically detects most of the system's hardware, including network
cards, disk drives, and PCMCIA.

cdrom-detect

Looks for and mounts a Debian installation CD.

netcfg

Configures the computer's network connections so it can communicate
over the internet.

iso-scan

Searches for ISO images (.iso files) on hard drives.

choose-mirror

Presents a list of Debian archive mirrors. The user may choose
the source of his installation packages.

cdrom-checker

Checks integrity of a CD-ROM. This way, the user may assure him/herself
that the installation CD-ROM was not corrupted.

lowmem

Lowmem tries to detect systems with low memory and then does various
tricks to remove unnecessary parts of debian-installer from the memory (at the
cost of some features).

anna

Anna's Not Nearly APT. Installs packages which have been retrieved
from the chosen mirror or CD.

user-setup

Sets up the root password, and adds a non-root user.

clock-setup

Updates the system clock and determines whether the clock is set to UTC
or not.

tzsetup

Selects the time zone, based on the location selected earlier.

partman

Allows the user to partition disks attached to the system, create file
systems on the selected partitions, and attach them to the
mountpoints. Included are also interesting features like a fully
automatic mode or LVM support. This is the preferred partitioning tool
in Debian.

partitioner

Allows the user to partition disks attached to the system. A
partitioning program appropriate to your computer's architecture
is chosen.

partconf

Displays a list of partitions, and creates file systems on
the selected partitions according to user instructions.

lvmcfg

Helps the user with the configuration of the
LVM (Logical Volume Manager).

mdcfg

Allows the user to set up Software RAID
(Redundant Array of Inexpensive Disks). This Software RAID is usually
superior to the cheap IDE (pseudo hardware) RAID controllers found on
newer motherboards.

base-installer

Installs the most basic set of packages which would allow
the computer to operate under Debian GNU/Linux when rebooted.

apt-setup

Configures apt, mostly automatically, based on what media the installer is
running from.

pkgsel

Uses tasksel to select and install additional software.

os-prober

Detects currently installed operating systems on the computer and
passes this information to the bootloader-installer, which may offer
you an ability to add discovered operating systems to the bootloader's
start menu. This way the user could easily choose at the boot time
which operating system to start.

bootloader-installer

The various bootloader installers each install a boot loader program on the
hard disk, which is necessary for the computer to start up using Linux
without using a floppy or CD-ROM. Many boot loaders allow the user to
choose an alternate operating system each time the computer boots.

shell

Allows the user to execute a shell from the menu, or in the second
console.

save-logs

Provides a way for the user to record information on a floppy disk, network,
hard disk, or other media when trouble is encountered, in order to accurately
report installer software problems to Debian developers later.